Planar optical waveguiding structures for application in communication networks are highly demanding with respect to low insertion loss, efficient fiber-to-chip coupling, polarization independent operation, high integration density, reliable fabrication, and last but not least cost efficiency. When applying silicon oxynitride, which is a very versatile material, planar waveguiding structures can be designed having the potential of meeting all those requirements. In this paper, we will describe the design of such a waveguiding structure, demonstrate the practical feasibility of realizing this structure and discuss the preliminary measurement results.
Kerstin rhoff, Paul V. Lambeck, and Alfred Driessen, "Design, Tolerance Analysis, and Fabrication of Silicon Oxynitride Based Planar Optical Waveguides for Communication Devices," J. Lightwave Technol. 17, 1401- (1999)